In the weeks after the alleged beating, Vargas was arrested on two counts of aggravated assault and battery with a dangerous weapon -- a shod foot and the cement sidewalk, according to prosecutors.

Following that arrest, he remained in custody, said Jake Wark, a district attorney spokesman.

Thirteen months after the altercation, Costa died of complications from the injuries he suffered during the incident, officials said. State pathologists declared his death a homicide, prompting Vargas’s indictment last month for the additional charge of murder.

But on March 24, 10 days after the murder charge was filed, Vargas was able to post bail because of “a clerical error with the warrant that should have held him,” Wark said.

When Vargas failed to show at an arraignment scheduled for April 9, authorities began searching for him, prosecutors said.

On Nov. 2, 2010, Costa and a friend were waiting for a bus on Meridian Street in East Boston, according to investigators. Costa noticed Vargas nearby and pointed him out as someone with whom his friend had a prior dispute. Vargas allegedly heard the exchange then approached the two men.

Vargas assaulted both men, knocking Costa to the ground before kicking and beating him, authorities said. Vargas at one point braced himself with a nearby fence as he stomped on Costa.

Costa was rushed to Massachusetts General Hospital with serious injuries. He remained hospitalized until his death on Dec. 17, 2011..

Matt Rocheleau can be reached at mjrochele@gmail.com. Jaclyn Reiss can be reached at jreiss.globe@gmail.com.